公开(公告)号：US5298991A

公开(公告)日：1994-03-29

申请号：US918010

申请日：1992-07-24

申请人： Yoichi Yagasaki ,  Jun Yonemitsu ,  Veltman Mark ,  Kaisuji Igarashi

发明人： Yoichi Yagasaki ,  Jun Yonemitsu ,  Veltman Mark ,  Kaisuji Igarashi

IPC分类号： H04N7/32 ,  H03M7/30 ,  H04N7/26 ,  H04N7/30 ,  H04N7/36 ,  H04N7/50 ,  H04N7/157

CPC分类号： H04N19/517 ,  H04N19/51 ,  H04N19/61 ,  H04N19/13 ,  H04N19/91

摘要： A ROM containing a variable length coding table for a 2 picture element range is provided. A motion vector within the range of 2 picture elements is provided to the ROM to produce a VLC code corresponding to the motion vector within the range of 2 picture elements. In a calculation circuit, assuming that the value of a motion vector within the range of 4 picture elements is X, a quotient Y and a remainder Z are obtained by the division of X by 2. The quotient Y is supplied to the ROM and the output of the ROM is added the remainder Z at an addition circuit to obtain a VLC code corresponding to the motion vector lying within the range of 4 picture elements. This is equivalent to variable length coding for a 4 picture element range. By transmitting a flag indicating whether the motion vector range is 2 picture elements or 4 picture elements, the motion vector is correctly reproduced from the VLC code. Accordingly motion vectors within the ranges of 2 picture elements and 4 picture elements can be coded using a single ROM table so that the hardware requirements are reduced.

摘要翻译： 提供了包含2个像素范围的可变长度编码表的ROM。 将两个图像元素范围内的运动矢量提供给ROM，以产生对应于2个图像元素范围内的运动矢量的VLC代码。 在计算电路中，假设在4个图像元素的范围内的运动矢量的值为X，则通过将X除以2获得商Y和余数Z。商Y被提供给ROM，并且 ROM的输出在加法电路中加上余数Z，以获得与4象素范围内的运动矢量对应的VLC码。 这相当于4像素范围的可变长度编码。 通过发送指示运动矢量范围是2个像素还是4个图像元素的标志，从VLC代码正确地再现运动矢量。 因此，可以使用单个ROM表来对2个图像元素和4个图像元素的范围内的运动矢量进行编码，从而降低硬件要求。